Air vent or inlet for plumbers  traps



(No Model.)

- W. MoELROY.

, AIR .VENT OR INLET FOR PLUMBERS TRAPS'. No. 244,468.

Patented Jilly 19,18 81.

I'NVENTCJRL UNITED STATES PATENT OF ICE.

WILLIAM MOELBOY, OF BROOKLYN, NEW YORK.

' AIR VENT OR INLET FOR PLUMBERS TRAPS.

SPE CIFICATION formingpart of Letters Patent No. 244,468, dated July 19, 1881.

"" Application filed December 1,1880. (No model.)

certain new and useful Improvements in Air Vents or Inlets for Plumbers Traps, of which the following is a specification.

Myinvention relates to that class of valves which open and admit air'when a partial vacuum is formed behind or beneath them, and which close automatically when an equilibrium is established, the object being to provide a valve for admitting air to a plumbers trap,so

that siphoning, so called, may be prevented.

The invention consists'partly in the construction of the valve itself, and partly in its arrangement with reference to the basin and trap with which it is connected all as will be more fully hereinafter set forth.

In the drawings which serve to illustrate my invention, Figure 1 is a general view of the valve and its casing in mid-section, showing its connection with the trap. Fig. 2 is a horizontal section of the valve and its casing, taken in the plane of the line 00 m in Fig. 1. Fig. 3 is a plan of Fig. 1. Fig. 4 is a view of the rubber valve detached, arranged to illustrate its action. Figs. 5, 6, and 7 are sectional views illustrating modified forms of the valve and its casing.

Let A represent the arch of a trap of any kind, and B a screw plug or tap inserted in the same to form a nipple, to which is attached a tube, 0, preferably of rubber. This tube is long enough to reach up to or above the bowl or basin connected to the trap, and to its upper end is attached a valve-casing, D. Although in. some cases it may be made of metal or other materials, I prefer to make this casing D of glass, partly because its transparency allows the interior to be readily inspected, and partly because it is sightly and not liable to tarnish or corrode. As a means of securing the casing to the wall, or to some other part, it may be encircled with a band, It, provided with a screw, 1), which may be screwed into the wall, or the band mayhave ascrew-plate in lieu of the screw b, and this plate may be screwed to the wall. The upper margin of the casing D is provided with a rabbet or groove arranged to receive a glass or metal cover, 0, which forms a hollow coned valve-seat. This coveris held in place by means of an annular elastic flanged cap, 0, preferably of rubber, the flange of which takes over the margin of the casing or over a bead on the same. This cap holds the cover firmly but elastically in place.

On an internal ledge formed in or attached to the casing sits the valve E, which isof rubber or some similar elastic material, of a cylin- 6o drical or tubular form, and provided with a coned top, f,whicl1-fits the valve-seat and forms the valve proper. I prefer to thin the walls of the cylindrical part of the valve, as at 9, so that it may yield the more readily to pressure downward on f by bulging out, as shown in Fig. 4. The dotted lines indicate the form of the valve when in its normal condition, and the full lines its form when depressed, but somewhat exaggerated. When in its normal position in the casing,as illustrated in Fig. 1, the valve E is sufficiently compressed to insure W an air-tight closure, but no more.

The operation is as follows: When,from any cause, a vacuum or partial vacuum is formed in the trapA, the outer air, pressing on the conical head f of the valve E, compresses it and enters the annular space around the valve within the casing. From thence it passes through openin gs h in the wall of the valve, and thence to the trap through the tube O, as indicated by the arrows. As soon as the equilibrium has been established the valve assumes its normal form and closes the inlet.

By arranging the valve above the basin I 8 5 obtain two advantages-it is visible and under the eye at all times, and it is entirely beyond danger of having fluid injected into it by a sudden stoppage or overflow. The casing being open at all times to sewer-gas, (as is the case 0 with all valves of this character,) it is important that the valve should be convenient for inspection at all times, and where it may be tested and examined every day. 7 This convenience of inspection will also serve as a guard 5 against the sticking of the valve, as well as against its leaking.

By means of my nipple B the householder may connect the vent with a trap by simply drilling a small hole and screwing in the nip- 10o ple. At any time that it may be desirable to remove the nipple a screw plug or stopper may be screwed into the hole in the trap. Such a screw-plug may be sold with the vent.

In Fig. 5 I have shown the valve-seat formed in the rubber cap, which is stifl'ened by metal lic washers. The valve-seat being of rubber I form the valve proper of glass or metal secured to ahollow globular rubber stem. The valve is perforated so as to open the hollow of the globular stem to the external air.

In Fig. 6 I have shown a metal casin g with a valve-seat formed in a cap screwed thereon. The valve is of rubber, oblong, hollow, and somewhat egg-shaped. This valve rests in a cup-like support fitted into or forming a part of the casing.

In Fig. 7 I have shown an inversion of the valve and seat. In this construction the valve fits over the seat instead of into it. In other respects it operates the same as those just described.

I am fully aware that valves of rubber have been held up to their seats by the retractile elastic force of india-rubber tubes connected therewith, and that such valves have been provided with rigid stems passing through said tubes, whereby the valves might be pushed away from their seats by stretching the rubber tubes connected with them; but I am not aware that a valve having a rubber stem and arranged to be drawn away from its seat by the bulging or bending outward laterally of said hollow stem has ever been employed. I do not claim, broadly, the employment of the elastic force of rubber to hold a valve to its seat, as that is not new.

I am aware that my valve and easing might be given a variety of forms without any departure from the principle of operation, and I do not limit myself to the exact forms shown.

Having thus described my invention, I claim- 1. A vent-valve for traps and similar purposes, having a stem made from elastic yielding material, whereby the valve is permitted to lift from its seat by the lateral bending of the said stem, and is held up to its seat by the elastic tendency of the stem to assume its normal position or shape, substantially as set forth.

2. A vent-valve for traps and similar uses, having a hollow, tubular, or globular stem made from elastic yielding material, whereby the said valve is permitted to lift from its seat by the lateral bulging or bending outward of the sides of the stem, and is held up to its seat by the elastic tendency of the sides of the hollow stem to assume their normal position or shape, substantially as set forth.

3. The combination of the casing D, the cover 0, containing the valve-seat, the cap 0, flanged to take over the casing, and the valve E, all arranged substantially as set forth.

4. The combination of the casing D, the seated cover 0, the elastic cap 0, and the hollow tubular-stemmed valve E provided with perforations it, all arranged substantially as set forth.

5. The combination, with the trap, of the screw-plug or nipple B, the tube 0, the casing D, the seated cover 0, the elastic cap 6, and the valve E, all arranged to operate substantially as set forth.

In witness whereof I have hereunto signed my name in the presence of two subscribing witnesses.

WILLIAM MCELROY.

Witnesses HENRY CONNETT, ARTHUR O; FRASER. 

